The present invention relates generally to optical communication systems and, more particularly, to a high-density optoelectronic (O/E) transceiver for high speed, parallel optical communication data links.
There are many well-recognized benefits of using optical fiber to replace copper wiring for printed circuit boards (PCBs) in computer and networking equipment. Such potential benefits include increased bandwidth and data rate, overcoming bottlenecks in the processing architecture, immunity to electromagnetic interference and reductions in radiated noise from the system, reduced latency by elimination of optical/electrical (OLE) conversions, more dense packaging at lower cost per pin, and enablement of new processor interconnect technologies such as meshed rings. These and other factors directly contribute to the performance of the computer system (e.g., increased processing power in MIPS (million instructions per second) or FLOPS (floating-point operations per second), increased node count in parallel architectures, etc.).
With the dramatic increase in processor speed over the last several years and the anticipation that this trend will continue, the copper interconnect technology will be unable scale to the bandwidth requirements of the processing units. Fiber optic components, on the other hand, do not suffer from the bandwidth/distance constraints of copper and are thus becoming a preferred medium for very high bandwidth transmission between processing units. But, in order to fully realize these benefits, the optical fiber interconnect components should also continue to provide the same benefits of the existing electrical connection technologies.
In certain applications, it is desirable to have an optoelectronic transceiver with the highest possible area density. The data bandwidth at which an O/E (optoelectronic) transceiver can transmit or receive information can be increased by increasing the serial data rate per each channel, increasing the number of channels, and/or sending and receiving multiple light wavelengths along each fiber with wavelength division multiplex technology (WDM) (i.e., employing dense wavelength division multiplexing (DWDM) or coarse wavelength division multiplexing (CWDM)). Typically, it has been cheapest and easiest to first increase the serial data rate, and then increase the number of channels. The use of DWDM or CWDM has generally been limited to cases where installing more optical fibers would result in a large enough expense to justify the use of DWDM or CWDM.
It is highly desirable to follow industry standards for O/E transceivers such that multiple sources of supply are available. However, this approach limits the number of fibers per unit area since, for parallel optics cables and connectors, the current industry standard is a 1xc3x9712 array with the fibers disposed on 250 micron ({circumflex over (l)}xc2xcm) centers with a MT ferrule for the connection. Newer standards are evolving based upon multiple stacked, 1xc3x9712 arrays (again with a MT ferrule for the connection). Because existing WDM and CWDM technologies generally require bulky optics and multiple edge emitting lasers of different wavelengths, this results in a relatively large space needed for accommodating WDM and CWDM O/E transceivers. Thus, it would be desirable to have a more compact and simpler means of implementing and forming a parallel DWDM or CWDM O/E transceiver.
The foregoing discussed drawbacks and deficiencies of the prior art are overcome or alleviated by an optoelectronic transceiver assembly including a plurality of optical transmission devices coupled to a first end of a multimode optical fiber core. Each of the plurality of optical transmission devices generates light at a different wavelength with respect to one another. A wavelength demultiplexing device is coupled to a second end of the multimode optical fiber core, and a plurality of optical detection devices is in proximity to the demultiplexing device. The optical detection devices receive light transmitted by the plurality of optical transmission devices.
In another aspect, an optoelectronic transceiver assembly includes a plurality of vertical cavity surface emitting lasers (VCSELs) butt coupled to a first end of a multimode optical fiber core. Each of the plurality of VCSELs generates light at a different wavelength with respect to one another. A hologram is butt coupled to a second end of the multimode optical fiber core, the hologram configured for demultiplexing light of the different wavelengths. In addition, a plurality of photodiodes is in proximity to the hologram, wherein the hologram is further configured to direct light of the different wavelengths to different ones of the photodiodes.
In still another aspect, a computer backplane interconnection system includes a first backplane having a first chip carrier associated therewith, and a second backplane having a second chip carrier associated therewith. An optoelectronic transceiver assembly provides signal communication between a first chip associated with the first chip carrier and a second chip associated with the second chip carrier. The optoelectronic transceiver further includes a plurality of optical transmission devices coupled to a first end of a multimode optical fiber core, with each of the plurality of optical transmission devices generating light at a different wavelength with respect to one another. A wavelength demultiplexing device is coupled to a second end of the multimode optical fiber core, and a plurality of optical detection devices is in proximity to the demultiplexing device. The optical detection devices receive light transmitted by the plurality of optical transmission devices.